Since the dawn of mankind fire has played a crucial part in our survival, keeping us warm in the coldest of climates, but now it poses a threat to our very existence.
Over 20% of the UK’s carbon emissions come from heating our homes with natural gas (methane), oil and coal. If we are to successfully address climate change, we must find alternative, sustainable fuels.
From 2025 onwards new homes being built will no longer have gas boilers fitted but what will they use instead and what about existing properties?
With the planned growth in renewable electricity generation, it might seem reasonable for us all to move to direct electric heating but that would require an enormous increase in the national power output and a major upgrade to the supply network, resulting in very expensive energy. However, by using electricity to power air- or ground-source heat pumps we can get around four times more heat from every unit of electricity, making them very cost effective to run.
Air source heat pumps are likely to be the best option for most well insulated homes. These are installed in a box on the outside of the property, drawing in air and extracting heat from it. Ground source heat pumps are more costly, because pipes would have to be laid underground in the garden to capture heat from the soil, but they are more efficient in cold weather. In both types, pipes take warmed water from the heat pump into your home, where they are connected to radiators which run at around 10-20 degrees lower temperature than current systems, which means almost certainly that larger radiators or underfloor heating systems are required. This adds to the already significant cost of retro-fitting heat pumps to an existing house, which can typically be between £8,000-16,000. Grants are however available to help offset the cost if certain conditions are met. The current scheme runs to the end of March 2022.
Hydrogen is another alternative on the horizon for the 80% or so homes in the UK already using natural gas. This gas produces only steam when burnt and, in principle, existing gas boilers could easily be converted, at relatively low cost, to use it. Hydrogen gas however does not occur naturally and must therefore be manufactured, which for low-carbon or ‘green’ hydrogen made by passing electricity through water, is a high cost. Hydrogen can be produced at lower cost from natural gas but that results in carbon dioxide emissions and whilst a high proportion of these could be captured and stored underground, it makes this a less attractive option.
The production of lower cost ‘green’ hydrogen is being explored by a number of chemical companies and Northern Gas Networks in Leeds is undertaking a project to ensure that hydrogen is safe to use in the national gas network, with the aim of converting the city of Leeds to hydrogen power by the early 2030s. Thus ‘green’ hydrogen remains a tantalising promise for the near future.
There are of course many poorly insulated, older properties in our district which are not on the gas network. Combine this with the high retrofit c